The present invention relates generally to food storage and rethermalization systems. In particular, it relates to systems used with food service carts which are loaded with trays of precooked meals and refrigerated to preserve the meals until time for service and are then heated to rethermalize the meals.
In the food service industry it is often desirable to prepare a large number of a variety of meals which can be stored in refrigerators for eventual service a day or more in the future. Some of the refrigerated foods such as meats and vegetables should be heated to high temperatures before serving while other foods such as fruits, salads and dessert should remain chilled. In many cases, a variety of meals must be made available to allow for the diners' individual tastes. In specific circumstances, especially hospitals, diets must be controlled, thus necessitating an even greater variety of meals which must be preserved and later served.
One known way of rethermalizing the precooked meals after refrigerated storage is by use of a cart which is provided with a separate means for heating selected compartments within trays that are to be used to serve the meals. When the meals are initially assembled, the courses which will require heating can be placed in the compartments which can be heated. Foods which should not be heated can be placed in nonheatable compartments. Hence, whether a dish is to be heated or not is determined when a member of the kitchen staff places the food in a specific compartment or container of a tray.
Such a method of heating the individual compartments is disclosed in U.S. Pat. No. 4,005,745 to Colato et al and French Patent No. 1,219,352 to Tricault. The serving tray is provided with covered containers which can be inserted into a specified opening extending through a tray. When the tray is inserted into a cart for storage in a refrigerator, the bottom of the specified containers are disposed on heating elements which act to lift the containers out of contact with the surface of the tray. When the meal is to be heated, an electric current is provided to the heating elements by a manually operated switch. Since the specified containers are covered and out of contact with the tray, very little heat is transferred to any other unheated container on the tray and thus other courses remain chilled.
In the systems known to the applicant, the personnel reheating the food must manually operate a switch to heat the various compartments which are to be rethermalized. Thus the personnel assembling the meals must record an extensive list of the trays which need heating in order to provide the servers with information as to which switches should be thrown to heat the proper containers. Alternatively, the servers must inspect every compartment of every tray to determine whether the electrical heater must be switched on. Either of these operations can consume time and provide opportunity for costly human error.
Hence, it is an object of this invention to provide an electrical system for a food service apparatus in which the food assembler can determine at the time he inserts the tray into the cart whether selected compartments of the tray are to be eventually reheated.
A further disadvantage to the use of manually operated switches is in the possibility that switches associated with unoccupied shelves may be left in an "on" position. Not only does this waste electricity but the heat generated by the areas on these unoccupied shelves may be transmitted to the chilled food in adjacent food trays.
Hence, it is a further object of this invention to provide an electrical system for food service devices in which the absence of a tray on a given shelf will render the heating areas for that shelf inoperative.
In the rethermalization of the meals which have been stored in the refrigerator it is necessary to apply heat for a predetermined period of time. Furthermore, it is desirable to allow the food to stand for a short duration following the heating but before the service of the meals. All the meals in the cart can be ruined if heat is not applied for the correct duration of time, or if the food is allowed to stand too long before service.
Hence, it is an object of this invention to provide an electrical system for a food service device which can automatically control the duration of time for which the food is to be heated and allowed to stand before service or to keep warm for a predetermined period of time.
Because food rethermalization systems use electricity for heating it is essential that the necessary electricity be supplied in a manner that is safe and desirable so that the users of such equipment have no or a minimum of difficulty in establishing the electrical connection.
Therefore it is another object of this invention to provide a novel food rethermalization, including means for simply and safely establishing necessary connections.